Human protein C (hPC) is a regulator of homeostasis, suggesting its potential use as a therapy for many disease states. Protein C is a zymogen of a serine protease that is activated by thrombin. Protein C, also known as autoprothrombin ⅡA and blood coagulation factor ⅪⅤ, is a zymogenic (inactive) protein, the activated form of which plays an important role in regulating blood clotting, inflammation, cell death and maintaining the permeability of blood vessel walls in humans and other animals. hPC is a 62 KD disulfide- linked heterodimer consisting of a 21 KD light chain and a 41 KD heavy chain which circulates as an inactive zymogen in plasma. In this study, we focus on generation of hPC transgenic mice. hPC transgenic mice were produced by using micro-injection method. The hPC cDNA was cloned into pBC1 vector under goat β-casein promoter. One-cell stage embryos microinjected were transferred to 24 recipient mice on day 1 of the estrus cycle. We screened 61 mice by the PCR. Four line transgenic mice were identified and confirmed expression of protein C gene in mammary gland and several organ. We also analyzed the expression of mRNA and protein through the northern blot and western blot in mammary gland of hPC transgenic mice. hPC was localized in the alveolar epithelial cell by immunohistochemistry. Now, we are collecting the milk from the 2 found lines. After then, we are checking the activity of hPC produced from mice milk.